1. Field of the Invention
This invention relates to an adjuster which is used to eliminate the vibration of a structure (such as a copying machine, a refrigerator and a desk) which is installed on the floor, thereby to allow the person to use the structure steadily.
2. Description of the Related Art
In general, in a copying machine installed on the floor of an office or the like, its cabinet is supported with casters at the four corners so that it can be readily moved. In the case where the floor on which the copying machine is to be installed is flat, the four caster are all set on the floor; that is, the copying machine is held stable. However, if the floor is not flat or curved, one of the casters rises above the floor, so that the cabinet is liable to vibrate. If the cabinet vibrates, then not only it is impossible to stably use the copying machine, but also the vibration adversely affects the precise mechanism of the copying machine. Hence, in general, an adjuster is employed to eliminate the vibration of the copying machine.
In FIG. 7, reference numeral 50 designates a conventional adjuster. FIG. 8 shows the arrangement of four casters 3 and two adjusters 50 on the cabinet 2 of a copying machine 1. Each of the adjusters 50 comprises: a bolt 53 including a head 51 and a threaded portion 52; and a rotary plate 54 which is coupled to the head 51 of the bolt 53 in such a manner that it is rotatable with respect to the bolt 53. The threaded portion 51 of the bolt 53 is screwed into a threaded hole 4b formed in the base 4 which is the bottom of the cabinet 2. The threaded holes 4b are provided at both ends of the base 4 on the side of operation of the cabinet 2 (on the forward side, or the lower side in FIG. 8). Usually, first the bolt 53 is screwed into the threaded hole 4b to the extent that the rotary plate 54 is somewhat spaced away from the floor F. And in the case where the cabinet 2 is vibrated, the adjuster 50 on the side of vibration is protruded towards the floor F by turning the bolt 53 with a tool such as a spanner until the rotary plate 54 touches the floor F. Instead of the threaded hole 4b, a nut may be employed which is secured to the base 4.
When all installation places or all floor conditions are taken into consideration, each copying machine must have two adjusters. However, in practice, installing places which require the adjusters 50 are very few. Hence, in most cases, it is not useful to equip the cabinet with the adjusters. In addition, the provision of the adjusters results in an increase in manufacturing cost of the copying machine. Furthermore, it is necessary for the copying machine to have a tool to turn the bolt 53. To turn the bolts 53 takes time and labor. To equip the copying machine with the tool results in an increase in manufacturing cost of the copying machine as much.
When it is required to move the copying machine, the copying machine is moved by means of the casters 3 with the adjusters 50 raised above the floor F. If the floor F has a step, in order to move the copying machine over the step the adjusters must be sufficiently raised above. This is rather troublesome. If the step is large, then the adjuster or adjusters 50 may be damaged being struck against the step.